Taxonomic note: Originally published in many websites as Philine aperta (Linnaeus, 1767), it has changed to Philinopsis miqueli Pelorce, Horst & Hoarau, 2013 and, later, to Melanochlamys miqueli (see Zamora-Silva & Malaquias, 2017). Both species are differentiated by their geographical area, M.miqueli is Mediterranean while P.aperta is located in South Africa (Price, Gosliner Valdés 2011). M.miqueli can also be confused with Philine quadripartita but physically Philine is larger (up to 70mm against 13mm for M.miqueli), it has a trapezoidal shaped body rather than cylindrical, the edge of the parapodia are not coloured bright white and the parapodia are separated from the body.
Philinopsis miqueli Pelorce, Horst & Hoarau, 2013
Description Animal with a cylindrical body of about 4mm in diameter and a maximum recorded length of 13mm. The body is translucent but it is covered by a multitude of small white dots that give it its uniform white appearance. The edge of the parapodia, cephalic shield and posterior edge are of a much more intense white color, a characteristic feature of this species. The cephalic shield covers practically half the length of the back. It also has a posterior dorsal shield (invisible to the observer) that starts slightly below the cephalic shield and extends backwards, where it ends in a more or less circular shape depending on the specimen. The base of the body forms a kind of roll, opened at the back, which gives it the appearance of a hollow cylinder from behind. It lacks a flagellum in the posteriot part. The foot is almost as long as the body and is flanked by two small parapodia, whose arched edge are attached to the body. The genital orifice is located in the right posterior part of the body, protected by the parapodium on that side and the rear shield. It does not have a radula (an evolutionary feature of the Aglajidae) nor gastric plaques. It has an internal, calcified, very thin and fragile shell that ends in a spiral of one and a half turns and that has a thickened edge, characteristic of this species. It has a mucous gland in the front of the foot and a gland in the back of uncertain use, which can produce a yellow substance when the animal is disturbed, but it is speculated if it has defensive or attack purposes (to paralyze its preys).
Biology Lives on rocky or pebbled bottoms between 1 and 5 meters deep. It can also be found in sandy bottoms. Its diet is not known, but the members of the Aglajidae family are voracious carnivores, some of which feed on other cephalaspideans (e.g. of the genus Bulla or Haminoea). The food of this species has not been documented, although it is inferred from its anatomical characteristics that it swallows its preys whole. The spawn consists of a thin string of transparent mucus containing light yellow coloured eggs, forming a kind of tube that is fixed on the algae that cover the substrate so that they are not at the mercy of the waves. Like the other Aglajidae, it has a gland in the anterior part of the foot that allows it to secrete a continuous flow of mucus that allows it to move quickly and even to bury itself easily, so it can survive in areas beaten by the swell. This mucus track allows other specimens to locate it to reproduce. It has also been observed a trailing behavior between two or more individuals, on which it has been speculated that a quick turn of the first specimen would allow it to perform a copula with the second specimen. It has not been observed that it is able to escape swimming with its parapodia, unlike other members of the family such as Aglaja tricolorata or Philinopsis depicta.
Melanochlamys. From Greek “melan”, black + “chlamys”, tunic.
Miqueli. Dedicated to Jean-Pierre Miquel, diver, photographer and collector, who was involved in the scientific description of the species, providing the type material and also obtained the inner shell.
Distribution This species lives in the Western Mediterranean, where its type locality is located: Calanque du Mugel, Marseille, France. It is known from the Spanish coasts to the island of Malta, also in the Adriatic Sea.
Known georeferenced records of the species: Melanochlamys miqueli
Ballesteros, M., E. Madrenas, and M. Pontes. 2016. Actualización del catálogo de los moluscos opistobranquios (Gastropoda: Heterobranchia) de las costas catalanas. Spira 6(2016): 1-28.
Bielecki, S., G. Cavignaux, J. M. Crouzet, and S. Grall. 2011. Des limaces de rêve.
Bucquoy, E., P. Dautzenberg, and G. Dollfus. 1886. Les mollusques marins du Roussillon, Tome I, Gastropodes. J. B. Baillière & fils. Paris: 487-570 pp.; pls. 61-66.
Dacosta, J. M., M. Pontes, A. Ollé i Callau, and L. Aguilar. 2009. Seguiment de mol·luscs opistobranquis a la platja des Caials (Cadaqués, Alt Empordà). Contribució al catàleg del Parc Natural de Cap de Creus. Annals de l’Institut d’Estudis Empordanesos. 40: 107–130.
Domènech, A., C. Ávila, and M. Ballesteros. 2006. Opisthobranch molluscs from the subtidal trawling grounds off Blanes (Girona, north-east Spain). J. Mar. Biol. Ass. U.K., 86: 383-389.
Flanders Marine Institute. 2018. Maritime Boundaries Geodatabase: Territorial Seas. Maritime Boundaries Geodatabase. (http://www.marineregions.org/).
Giribet, G., and A. Peñas. 1997. Fauna malacológica del litoral del Garraf (NE de la Península Ibérica). Iberus 15 (1): 41-93.
Hidalgo, J. C.1917. Fauna malacológica de España, Portugal y las Baleares. Trabajos del Museo Nacional de Ciencias Naturales. Serie Zoología (Madrid) 30: 752 pp.
Long, S. J.2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
Pelorce, J., D. Horst, and A. Hoarau. 2013. Une nouvelle espèce de la famille Aglajidae (Gastropoda: Opisthobranchia) des côtes de Méditerranée française. Iberus, 31(2): 165-170.
Prkić, J., A. Petani, Ð. Iglić, and L. Lanča. 2018. Stražnjoškržnjaci Jadranskoga Mora: Slikovni Atlas i Popis Hrvatskih Vrsta / Opisthobranchs of the Adriatic Sea: Photographic Atlas and List of Croatian Species. Ronilaćki Klub Sveti Roko, Bibinje.
Ros, J.1973. Opistobranquios (Gastropoda: Euthyneura) del litoral ibérico : Estudio faunístico y ecológico. Tesi doctoral. Universitat de Barcelona.
Ros, J.1978. Distribució en l’espai i en el temps dels opistobranquis iberics, amb especial referencia als del litoral catalá. Butll. Inst. Cat. Hist. Nat., 42 (Sec. Zool., 2): 23-32.
Zamora-Silva, A., and M. A. E. Malaquias. 2017. Molecular phylogeny of the Aglajidae head-shield sea slugs (Heterobranchia: Cephalaspidea): new evolutionary lineages revealed and proposal of a new classification. Zoological Journal of the Linnean Society, 2017, XX, 1–51.